Furnace construction



0612. 27, 1931. l SHEAHAN 1,829,159

FURNACE CONSTRUCTION Filed Dec 9, 1927 2 Sheets-Sheet 1 0d. 27, 1931. F,SHEAHAN 1,829,159

FURNACE CONSTRUCTION Filed Dec.- 9, 1927 2 Sheets-Sheet 2 @gw/zwf @QWPatented @ct. 27, 1931' warren srATEs PATENT OFFICE FRANK l. SHEAHAN, OFCHICAGO, ILLINOIS, ASS-IGNOR TO M. H. DETRICK COMPANY OF CHICAGO,ILLINOIS, A CORPORATION OF ILLINOIS FURNACE CONSTRUCTION Applicationfiled December 9, 1927. Serial No. 238,851.

This invention relates to furnace. construction and has to doparticularly with the construction and support of the furnace walls.

In various kinds of furnaces'it is frequently desirable to employ ahollow wall construction in which air chambers or passages are providedbetween an interior refractory wall pose of enclosing the boiler. Sincethese boiler walls preferably are built of solid masonry, and frequentlyare of considerable height, the supporting of them above the hollow wallof the furnace chamber has presented serious difficulties, because oftheir great weight and the elevation at which they must be supported. Ininstances, the boiler walls have been supported on heavy steel beams,which in turn are supported on heavy columns at their ends. Sucharrangements, however, in addition to involving dis-proportionateexpense, because of the large amount of structural steel necessary,involve difficulties in the cooling of the supporting beams and theirprotection from heat, as well as the effective bracing of them againsttorsion, and the effective joining up' of the furnace wall with theboiler wall.

The present invention involves a construction wherein the furnace wallis of the hollow type suspended in sections on a metallic framework,while the superimposed boiler wall which forms, in efiect, an upwardcontinuation from the furnace wall, is likewise carried on the metallicframework, without imposing any weight on the refractories or bricks ofthe furnace wall.

The general object of the invention is the provision of a constructionwhereby a heavy boiler wall may be supported above and in conjoiningrelationship with a suspended furnace wall by a metallic frameworkrequiring a minimum amount of steel and requiring no supplementarybracing in directions transversely of the wall.

Another object is the provision of a construction wherein a suspendedfurnace wall and a superimposed wall may be supported on a metallicframework, with liberal spacing of the frame members from therefractories which are exposed to the furnace heat, and liberal exposureof the metallic frame memhere to cooling air, without imposing on theframe members tilting forces, due to eccentric loading, of suchmagnitude as to necessitate supplemental bracing for supporting them.

Another object is the provision of a construction wherein a superimposedwall may be supported in conjunction with a subjoined suspended wall oncolumns disposed laterally and exteriorly of the walls, withoutsubjecting the suspended wall to the weight of the superimposed wall.

Other and further objects will be pointed out or indicated hereinafter,orwill appear to one skilled in the art upon an'understanding of theinvention or its employment in practice.

In the accompanying drawings forming a part of this specification Iillustrate portions of furnace wall construction embodying theinvention, but it is to be understood that these are here presented forthe purpose of illustration only, and are not to be accorded anyinterpretation having the effect of limiting the claims short of thetrue and most comprehensive scope of the invention in the These viewswill serve to illustrate a construction wherein a superimposed wall ofsolid masonry construction, designatedgenerally by the reference numeral10, is supported in conjoining relationship with a sectional suspendedwall of a furnace chamber, which suspended wall is designated generallyby the reference character 11, the construction being appropriate foruse in a boiler furnace. It will be understood that the term wall ashereinafter used, may apply to any one or all of the sides of thefurnace structure. Along the line of the wall are disposed, atappropriate intervals, supporting columns 12 with their radius ofmaximum stiffness disposed in a direction transversely of the WalL- Theyare anchored at their bottoms to suitable foundation members byconnecting means 14, and carry at suitable vertical intervals thesections supporting members 15, which extend longitudinally of the walland which are here shown as channel members attached to the innerflanges of the column members 12. At their tops, the column members 12carry the brackets 16 extending inwardly of the wall, and upon thesebrackets and secured thereto is carried'a tie member 17 which functionsalso as a support for the superimposed wall and the upper section of thesuspended wall. This tie member is here illustrated as a channel withits radius of maximum stiffness extending in a direction transversely ofthe wall. At its ends this tie member is tied to the boiler columns 18,as by the angle pieces '19. Thus, the tie member 17 finds support atproper intervals on the brackets 16 and columns 12, so that it isrendered quite stifl' in the vertical direction, and it, in turn, formsa connection between all of the columns 12 which is very stifl in thedirection transversely of the wall, and being anchored to the boilercolumns at its ends, in addition to holding the columns 12 in aligmnent,it holds them against tilting inwardly.

The suspended wall 11 is subdivided into a plurality of zones 11a, oneabove another, each made up of a row of collaterally arranged sections.Each section is formed of a stack of refractories 20 supported on ahanger 21. Each hanger has at its upper end a tension arm terminating ina hook 21 which engages over the inner flange of one of the members 15or, in the case of the upper rowv of hangers, the inner flange of thetie member 17, and at its lower end a compression arm terminating in afoot 21 which bears against the inner flange of the next lower member15. The refractories on each hanger are supported on a shelf 21 andanchored to a vertical flange 21, which fits in slots in the outer endsof the refractories. The hangers of adjacent zones are arranged instaggered relationship, so that the vertical joints between sections inadjacent zones are broken. With the sections thus supported, therefractories form a continuous refractory wall for the furnace chamber,the refractories in each section being supported independently of thosein all other sections, so that the weight or expansion pressure of nosection is imposed on another. Expansion space is left between adjacentzones,- and filled with a compressible refractory material, toaccommodate the expansion of the respective sections. An outer orsheathing wall 22- is supported in sections on the members 15.

The hangers 21 of the uppermost zone are provided at the top withshelves 21 extending the full length of the compression arm andprojectin inwardly beyond the vertical flange 21 rom the shelf 21projects upwardly a short lug 21, in line with the flange 21. A courseof refractories is positioned on the shelves 21, finding anchorage bytheir slots on the lugs 21. On this top course of refractories, and onthe shelves 21 and on the web of the tie 17, is supported thesuperimposed wall 10, which is built up in the customary fashion to theheight necessary to enclose the boiler, an expansion space beingprovided between the course of refractories on the shelves 21 and thecourse immediately below it.

By this construction, it will be observed, both the sectional wall andthe superimposed wall are carried on the column members 12, but sincethey are positioned entirely, or almost entirel inwardly of the columnmembers, or 0 their neutral vertical axis, it would appear that thecolumn members are subjected to heavy forces tending to tilt theminwardly and necessitating their being braced. By virtue of theconstruction, how-. ever, these apparent tilting forces are to a verysubstantial extent neutralized, so that the actual resultant is reducedto a value which easily can be supported by the anchorage of the tiemembers 17 at their ends, and taken by the boiler column quite safely.

The mechanics of the structure is illustrated in Fig. 3. The columns 12may be regarded as a series of stiff levers fulcrumed at P and rigidlyconnected at their tops by the tie member 17. The weight W1 of thesuperimposed wall on the uppermost row of hangers 21 produces a couplewhich exercises on the tie member 17 an inward force F which is equal toW, -d 1 H1 and which tends to swing the tie member and the columnsinwardly about the fulcrum P of the latter. This couple, acting throughthe uppermost hangers subjects the columns to an equal outwardly actingforce F at the uppermost member 15, which tends to swing Likewise, theweight of the topmost zone 11 producesthrough the uppermost hangers 21 acouple which exercises on the tiemember 17 an inward force F and on thecolumns at the upper member 15 an equal but outwardly acting force FEach of the lower zones, assuming them to be all of the same weight andheight and disposed the same distance from the axis of the columns,subjects the columns to equivalent inward and outward forces F, at therespective members 15, which forces cancel each other exce tin at thelowermost member 15, where the f orce is outward. The inwardly actingforce F on the tie member is consequently counteracted in part by anoutward statical moment F through the medium of the columns and becomesequal to 1 The reaction requisite to maintain the tie member inequilibrium is the summative value of the inward and outward forceseffective on it. Calling the inward forces positive and the outwardforces negative, their summative value is F +F F '-F which value isobviously appreciably less than the aggregate of F and F and can easilybe carried by the boiler columns without supplementary bracing. It willbe observed that the stiffest axis of the tie member 17 is in the laneof this horizontal force, thus qualifying that member to carry thehorizontal forces and reactions without bending and to distribute themequally among all the columns. It will be observed also that in thetransmission of these horizontal forces and P reactions the columnsfunction as levers fulcrumed at the base. It will be observed also thatthe bending moment exerted on the columns bg the weight of the superimosed wall throu the leverage of the braciets 16 is taken y the columnsin their plane of greatest stift'ness, and due to this fact, togetherwith the fact that the weight is ualiz ed among the columns through theme ium of member 17 they are able to carry the eccentrically actm weightof the superim osed wall without aving to be excessively eavythemselves.

In addition to effecting a very substantial saving in weight of theframe members by virtue of the features above described, theconstruction makes it possible to reduce the excess allowance in theweight of steel included as a safety factor against weakening byheating, as all of the steel work is liberally spaced from the heatedrefractories, with air-circulating space intervening, and with liberalexposure of the steel members to external air. In referring to thesteel, I do not wish to be understood as including the hangers 21, asthese are cast members, and consequently are not so quickly reduced intensile strength by heating as is steel. As seen in Fig 2, moreover, ina four-wall construction the tie member 17 of any one of threeconjoining walls function as a strut effective to brace the boilercolumns against the horizontal forces imparted to them by the tiemembers of the two adjoining walls.

The construction preserves all of the advantages of the sectional hollowwall including its flexibility, accommodation of expansion, avoidance ofheavy loading of refractories, cooling and air pre-heating features,facility of repair, etc., while permitting the building of thesuperimposed wall as an upward continuation of the suspended wall. Theweight of the tie member 17 need be only a small fraction of thatrequired in beams with end support, were such construction to be emploed for carrying the superimposed wall. y use of this construction thefurnace can be given a finished. external appearance, floor space may beconserved, because of the absence of external bracing and foundationrequirements are simplified because of the uniform distribution of theweight of the wall.

In the modified arrangement shown in Fig. 4, the various parts aredesignated by reference characters as in the other figures, with theexception of the tie member, which is designated 17'. In this arranement this tie member is secured to the co umns 12 at a point belowtheir upper extremities, and is anchored at its ends to the boilercolumns, as described in connection with the other embodiment. The uppertierof hangers 21,

upon which the superimposed wall 10 is suported, have their compressionarms disposed in cooperation with the tie member, so that the horizontalmoments exerted on the latter by the weight of the superimposed wall andthe topmost suspended sections are in'the outward direction. Leaving theeffect of the lower sections out ofconsideration, therefore, the nethorizontal thrust which the anchoring connections of the tie member haveto carry is represented, as explained above, by the difference betweenthe statical moments of the outward and inward forces on tions disposedone above another with expansion joints between them, a row of columnsranged alongside the furnace chamber wall, means cooperating with thecolumns at vertically spaced localities for supporting the respectivesections independently thereon, and a superimposed wall supportedentirely by the columns and forming an upward continuation from the topof the furnace chamber wall, an expansion joint being provided betweenthe topmost section of the furnace chamber wall and the superimposedwall.

2. In furnace construction, in combination, a row of columns rangedalongside the furnace chamber, a hollow furnace chamber wall supportedlaterally on the columns, and

a superimposed wall supported entirely by the columns above the hollowwall and forming an upward continuation thereof.

3. In furnace construction, in combination, a row of columns rangedalongside the furnace chamber, hangers supported-laterally on saidcolumns, a furnace chamber wall supported by said hangers, and asuperimposed wall supported entirely by said columnsabove the furnacechamber wall, said superimposed Wall resting in P 11 certain ofsaidhangers, and an expansion joint being provided between the furnacechamber wall and said superimposed wall.

4. In furnace construction, in combination,

a row of columns ranged alongside the fnrnace chamber, a tie memberrunning longia tie member connecting the columns adjacent their upperends to hold them in the desired ally thereof, and a superimposed wallsup alignment, anchoring means at the ends of the tie member holding itagainst shiftingtransversely, a hollow furnace chamber wall supported onthe columns and disposed laterported entirely by the columns and forminga top closure for and an upward continuation from the furnace chamberwall.

6. In furnace construction, in combination, a row of columns rangedalongside the fun nace chamber and anchored at their lower ends, a tiemember connecting the columns adiacent their upper ends to hold them inthe desired alignment. means anchoring the he member at its ends to holdit and the columns against swinging laterally, hangers extendinglaterally'from the columns, a furnace chamber wall supported 'on saidhangers, and

a superimposed wall resting partly on certain of said hangers andcarried entirely by the columns in a position above the furnace chamberwalls.

7. Iii furnace construction, in combination, a row of columns rangedalongside the furnace chamber and anchored at their lower ends, a tiemember rigidly connecting the columns adjacent their upper ends andanchored at its ends against shifting transversely, a row of hangersdisposed laterally of the columns and connected therewith at verticallyspaced localities, refractoriessupported on said hangers to form afurnace wall portion, and a superimposed wall supported on certain ofsaid han ers above said furnace wall portion, where y the weight of saidsuperimposed wall is transmitted to the columns through said hangersindependently of the furnace wall.

8. Infurnace construction, in combination,

a row of columns ranged alongside the fur- -nace chamber and anchored attheir lower ends, a tie member connecting the columns adjacent theirupper ends whereby to hold them in alignment, means anchoring said tiemember at its ends to hold it and the columns against moving laterally,said tie member ex-' tending laterall from the columns and having itsradius 0 maximum stiffness disposed horizontally, wall supportsconnected at their upper ends to said tie member, means for ber, meansanchoring one of said transverse members at its ends to hold it and thecolumns against swinging laterally, a wall sect1on supported by saidhangers laterally of the columns, and a superimposed wall supported bysaid hangers and disposed laterally of said columns, whereby the entireweight of said superimposed wall is transmitted to said columns as acouple.

10. In a boiler furnace, in combination, a row of columns rangedalongside the furnace chamber, a tie member connecting the columnsadjacent their upper ends, boiler col- .umns at the ends of the tiemember, means anchoring the tie member to'the boiler columns to hold thetie member against shifting laterally, hangers supported by the columnsand disposed laterally thereof, a furnace chamber wall carried insections on the hangers, and a boiler wall supported entirely on certainof the hangers and columns independently of the furnace chamber wall,said hangers cooperating with the tie member and columns. to transmittheir loading to the lat- ,ter as a couple.

11. In a boiler furnace, the combination with the boiler columns, ofwall supporting columns ranged along the sides of the furnace chamber,tie members connecting the wall columns on the respective sides of thefurnace adjacent their upper ends, said tie members anchored at theirends to the boiler columns and forming spacing, struts between theboiler columns, furnace walls suspended on the wall columns at theirinner sides, and boiler walls supported on the wall columns and formingupward continuations of the furnace walls.

12. In furnace construction, in combina tion, columns ranged along thefurnace chamber and fulcrumed at their lower ends a tie member connectedto the columns ad acent their upper ends, means anchoring the tie memberat its ends to hold it against shifting transversely, hangers disposedinwardly from the row of columns, suspended wall sections carried by thehangers laterally of the columns, a superimposed wall supported bycertain of the hangers above the suspended wall sections, andconnections between the hangers and columns whereby the loading carriedby the hangers is transmitted to the columns as a couple.

In testimony whereof I have hereunto subscribed my name.

FRANK- I. SHEAHAN.

